Heat the oil in a pan and fry the cinnamon, bay leaves, peppercorns, cloves and cardamoms for a minute over medium heat. Add the onion, ginger-garlic and green chili and stir-fry until the onion is golden. Add the curry powder and stir-fry for a minute. Add the tomatoes and cook for couple of minutes. Then add the ground lamb and salt. Mix thoroughly. Reduce the heat and cover the pan and cook for 10-15 minutes. Stir occasionally to prevent the mixture from sticking to the pan. Add the eggplant and mix thoroughly. Cover and cook for 10 minutes or until the eggplant is cooked. Stir occasionally. Serve hot.